Such camouflage blankets are described, for example, in the documents U.S. Pat. No. 4,479,994, U.S. Pat. No. 4,659,602, WO 2004/020931 and WO 1988/01363.
These known camouflage blankets are generally effective against radar detection, but conversely they provide only very low protection against detection by an observation device operating in infrared radiation bands I, II and III.
To solve this problem, it is conceivable to provide, in said known camouflage blankets, a layer treated for infrared concealment, positioned on the side intended to be directed outward from the equipment to be protected. However, the effectiveness of such a layer treated for infrared concealment is very limited for infrared bands I and II when there is sun during the day. This is because, even if the emissivity of said layer is low, the layers behind end up radiating by progressively storing up heat.
In addition, in the case in which (as in the document U.S. Pat. No. 4,479,994) such a camouflage blanket comprises a plurality of superposed layers, at least one of which consists of a flexible panel of a radar absorber able to absorb microwave radar frequencies at least partly, experience has shown that such a layer treated for infrared concealment causes the performance of the radar absorber positioned behind to deteriorate. This phenomenon is probably due to the fact that the infrared treatment requires the use of low emissivity pigments which are at least partly electrically conductive. This protective layer must locally cause a abrupt variation in impedance which is detrimental to the functioning of the radar absorber. This problem is all the more marked, if a lower emissivity complex is desired.